Welcome to Singapore! The information you are looking for can be found at the Ministry of Manpower ("MOM") website, under Work Permit (Foreign Domestic Worker).
I think the most important conditions that you should know are that your maid (the "FDW"; Foreign Domestic Worker) must be at least 23 years old and she must have at least 8 years of education. There is an "Entry Test" which she must pass within 3 days of entering Singapore. Also, you -- as the Employer -- will be required to attend a brief training course together with her within a few weeks of her arrival.
In view of the "Entry test", you may want to consider having your maid prepare for this in Indonesia, via an test preparation course provided by a maid agency in RI or SGP. Even if your maid is already experienced, the test prep will prepare her for the exam format.
I highly recommend paying a maid agency to handle all the paperwork. My family only hires FDWs that we recruit ourselves in their home countries, yet we still insist on going through a maid agency for the paperwork, even if it means paying the agent a commission that includes "recruitment fees" over and above the paperwork. It's just so much more efficient. It can be a sensitive issue because if the employer does not volunteer to meet the maid's share of this expense, it will mean that she has to borrow more money in order to come. In our family we cover this 0%, 50%, or 100%, on a case by case basis.
Oh well. I hope this was helpful. Wishing you and your family happiness in Singapore --
Auntie
[This message has been edited by BoardManager (edited 16-02-2007).]